Physics > Atmospheric and Oceanic Physics

Title:
Was Doggerland catastrophically flooded by the Mesolithic Storegga tsunami?

Abstract: Myths and legends across the world contain many stories of deluges and
floods. Some of these have been attributed to tsunami events. Doggerland in the
southern North Sea is a submerged landscape thought to have been heavily
affected by a tsunami such that it was abandoned by Mesolithic human
populations at the time of the event. The tsunami was generated by the Storegga
submarine landslide off the Norwegian coast which failed around 8150 years ago.
At this time there were also rapid changes in sea level associated with
deglaciation of the Laurentide ice sheet and drainage of its large proglacial
lakes, with the largest sea level jumps occurring just prior to the Storegga
event. The tsunami affected a large area of the North Atlantic leaving
sedimentary deposits across the region, from Greenland, through the Faroes, the
UK, Norway and Denmark. From these sediments, run-up heights of up to 20 metres
have been estimated in the Shetland Isles and several metres on mainland
Scotland. However, sediments are not preserved everywhere and so reconstructing
how the tsunami propagated across the North Atlantic before inundating the
landscape must be performed using numerical models. These models can also be
used to recreate the tsunami interactions with now submerged landscapes, such
as Doggerland. Here, the Storegga submarine slide is simulated, generating a
tsunami which is then propagated across the North Atlantic and used to
reconstruct the inundation on the Shetlands, Moray Firth and Doggerland. The
uncertainty in reconstructing palaeobathymetry and the Storegga slide itself
results in lower inundation levels than the sediment deposits suggest. Despite
these uncertainties, these results suggest Doggerland was not as severely
affected as previous studies implied. It is suggested therefore that the
abandonment of Doggerland was primarily caused by rapid sea level rise prior to
the tsunami event.